The invention concerns a method for producing chocolate in which a charge of cocoa paste and sugar, and optionally powdered milk, are mixed in a premixer with application of heat. The charge is subsequently fed into a first grinder and there prepulverized. Thereafter, the paste so obtained is subjected to conching treatment in at least one stirring device under temperature control, while substantially removing volatile components in the form of water and organic acids by means of a gas, particularly air, passed through the stirring device. Reactions between the organic components and the reactive carbohydrates of the cocoa paste or milk for the development of taste, addition of fat and emulsifiers, especially in the form of cocoa butter and lecithin, dispersion of fat and emulsifiers and flavorings, as well as the final liquefaction of the paste, are conducted in further steps. Furthermore, the invention concerns an apparatus for implementing this method.
Such a process for manufacturing chocolate is generally known, for which reason this will not be repeated here again in detail. Temperature and other operating conditions are especially known which are a precondition for the process of working the paste in the stirring device, also designated as the conche.
Such a stirring device consists in a known case of a horizontal mixing drum in which is arranged a rotor driven by an electric motor, optionally with a reversible direction of rotation, on which essentially radially directed mixing tools are axially distributed for axial and radial product movement. These mixing tools are so installed that they serve to scrape the paste from the mixing drum wall in one direction of rotation of the rotor, while promoting the unguent-like and paste-like consistency of the paste in the other direction of rotation. Moreover, the jacket on the mixing drum is constructed as a double jacket to which, for example, water can be fed as a heating or cooling liquid , depending on whether in the current stage of the tumbling process in the conche cooling of the paste is indicated for energy elimination or heating of the paste is indicated for maintaining the necessary operating conditions. Finally, the interior of the stirring device is ventilated with the aid of a blower for removal of volatile components accumulating during the operating process, whose presence in the finished chocolate is undesirable.
As is well known, chocolate production transpires between 45 and 120.degree. C., according to the stage of the process and recipe-related additives. Moreover, processing times generally lie in the range of 8 to 24 hours. Finally, processing in a conche especially requires considerable driving energy for the rotor of the stirring device, not only on account of the duration of the working process mentioned, but also in view of the work load which must be applied for mixing the paste and giving it an unguent and paste-like consistency. The known process is therefore lengthy and costly, also in view of the fact that a comparatively robust and complicated apparatus must be used for a certain amount of chocolate over a comparatively long period of time, so that a sufficient dwell time is available for the paste in the individual steps of the working process.
A further disadvantage of the known process consists in that in the conching treatment, removal of the volatile components, development of the taste, and drying are combined with liquefaction of the paste. This demands compromise solutions, since the individual component processes cannot be individually controlled or conducted. On the other hand, it cannot be prevented on this account that the conditions necessary for the individual component processes will mutually disturb each other, which consequently leads to impairments. The only possible way to avoid these again finds its expression in the long duration of the production process.
Thus, for example, attaining the desired taste of the product requires increasing the operating temperature due to the reactions necessary for it, which however can again lead to the volatile components, which are possibly needed for the reaction, being eliminated too soon.
In addition, with the known process, the semi-finished or finished chocolate is present in the conche as a homogenous paste or liquid phase, so that a gas, such as air, can barely come into contact with the chocolate paste for mass transfer, whereby certain reactions and the elimination of volatile components can be hindered.